Improvement in processes of making artificial marble



UNITED STATES PATENT OFFICE.

HARRIET G. HOSMER, OF ROME/ITALY.

IMPROVEMENT IN PROCESSES OF MAKING ARTIFlClAL MARBLE.

Specification forming part of Letters Patent No. 214,142. dated April 8, 1879; application filed November 29, 1878.-

To all whom it may concern:

Be it known that I, HARRIET Goonmm HOsMER, residing at Rome, in the Kingdom of Italy, have invented a new and useful Process for Making Artificial Marbles, which process is fully set forth in the following specifipreserve its natural color, or, i? it is desired to color the stone, in one of the various colored baths below described, according to the color desired.

In carrying out my invention, take the stone which has been carefully reduced to whatever finished shape is desired, whether as statues, architectural ornaments, or any of the forms in which marble is or can be used. Place the stone objects in a boiler furnished with a manometer, and lined, so that no rust can discolor the water, and also containing a grated platform at the bottom, so that earthy particles may sink and not adhere to the stone. I next fill the boiler with 'pure water, free from any mineral deposit,- (rain water is best,) and of natural temperature, taking care that the objects be entirely immersed. The boiler is then closed hermetically and heat applied, and the water allowed to boil until the manometer indicates 5 atmospheric pressure, it the objects are small, and 6 or 7 if they are large. Then the water is allowed to cool until the manometer returns to zero.

Instead of the boiling process above described, steam alone may be introduced into the boiler, care being taken that the same degree of heat and pressure is maintained, and the result attained will be the same.

If it is intended. that the objects shall preserve the natural colorof the stone, I next place them in a bath consisting of pure water containing five per cent. of alum, as indicated by the areometer, and let them remain for at least twenty-four hours. They may remain longer, if greater hardness is desired.

If water is used in the boiler, as before described, this alum-bath may be effected in the boiler itself, and in that case the alum is put in the water before the boiling begins, and the objects remain in the boiler twenty-four hours after the manometer returns to zero.

The alum-bath is only to be used when the natural color of the stone is to be preserved. If it is intended to color thestone, I take the objects from the boiler after the boiling or steaming process, and place them, according to the color desired, in any one of the various colored baths, the composition of which is given below, where they must remain entirely immersed at least twenty-four hours. I The colored bath inust be boiling, or very nearly so, at the time of the immersion, and it is better, though not essential, that the objects should be immersed while still warm from the 'boiler. An object may be immersed asecond time to give deeper color, first letting it remain ten minutes in an oven at a temperature of 80 or 90.

The following is the composition of the various colored baths, viz:

Black or dark gray.-Pure water, two liters; redwood, three hundred grams; fustic-wood, one hundred and twenty grams; sulphite of iron, ten grams; sulphite of copper, two and one-half grams. Boil-the redwood and fusticwood an hour and a-half. Then add the sulphites, and continue the boiling until all the salts are dissolved, (three or four minutes will generally be suflicient.) Then pass the solution through a sieve, and add a gill of acetic tincture of iron. The color augments with time.

Stone colon-This is made in the satne manner and with the same quantity of water, but

with half the quantity of all the other sub stances as in the composition of black above given. Care must be taken to refill the vase in which the liquid is prepared as the water diminishes by boiling.

Red-Pure water, three liters; vezzino, (or Brazilian wood,) three hundred and thirty grams; scotano, five grams; cream of tartar, one gram; alum, one gram. Boil until all the color of the wood is extracted, and then pass through the sieve.

Yellow-Pure water, three liters; extract of yellow wood of Cuba, twenty grams; sulphite of magnesia, (or alum,) ten grams. Boil until the solution of the extract is complete.

Green -lure water. three liters; extract of yellow wood of Cuba, twenty grams; alum, ten gram Boil until complete solution of extract; then add carefully, by means of a wooden spoon. as many drops of solt'o-indigotic acid (Saxon blue) as may be necessary to give the shade of color desired. plaster-of-paris may be used to test the color by dipping it in the solution.

Blue-Pure water, three liters; alum, ten grams: solt'o-indigotic acid, (Saxon blue.) as

much as in the previous composition of green,

until the color desired is obtained.

\Yhatever color which penetrates the stone perfectly and is a permanent color may be used at pleasure. Dissolve the color selected in a little alcohol. which is afterward diluted with warm water in which alum is dissolved, in the proportion oftwenty-t'our grains to every liter of Water. The preceding is for colors in soluble in water.

For such colors as are soluble in water, no alcohol is necessary. They may be dissolved in boiling water in which a little alum or sulphate of magnesia is introduced.

The same colors which are permanent in cloth are permanent in stone.

Finally, after the objects are removed from their respective baths, they are allowed to dry thoroughly, which may require a fortnight, or even more, according to the size. They are then polished-first with uimiee-stone, then with slate orlead. They are then rubbed with oil, and, lastly, after the oil is dry, with phosphate of lilne. This process of p'olishin; gives abrilliant and perfect luster. The ordinary methods of polishin; marble will, however, apply perfectly to this artificial marble.

1 am aware that heat. has been before applied to stone and gypsum for the purpose of making it resemble natural marble; but in all previous processes, so far as am aware, dry heat only has been so applied.

\Vhat is particularly new and useful in the process above described is the use of moist heat, or heat in the form of steam, which thoroughly penetrates the stone and makes it of umform hardness and density throughout.

I claim as my invention- 1. The process of preparing and treating; limestone or other like stone, includng; alabaster-stone. so that it acquires the appearance and uniform hardness t hroug'hout ot'natural marble in its various co ors. by the use of and application thereto of moist heat, or heat A piece of drV in the form of steam, in combination with a bath of alum and water, or with variou: baths composed of diti'erent chemicals and coloring: materials, substantially as described.

2. The process of preparing and treating limestone or any other like stone, including alabaster-stone, so that it acquires the appearance and uniform hardness and density throughout of natural marble, by the use of and application thereto of moist heat, or heat in the form of steam, in combination with a bath of alum and water, substantially as described.

3. The process of preparing and treating limestone or any other like stone, including, alabaster-stone, so that it acquires the appearance and uniform hardness and density throughout of natural marble in various colors, by the use of and application thereto of moist heat, or heat in the form of steam, in combination with a bath or baths composed of chemicals and coloring materials, substantially as described.

4. The process of causing limestone or other like stone, or alabaster-stone, to resemble or to acquire the appearance and uniform hardness and density throughout, or any of the qualities of natural marble, by the use of and application thereto of moist heat, or heat in the form of steam.

5. The process of preparing or treating limestone, alabasterstone, or other like stone, so that it may acquire the appearance or any of the qualities of natural marble, by the use of and application thereto of a bath of alum and water.

6. The process of preparing and beating; stone so that it acquires the appearance and uniform hardness throughout of natural marble in its various colors, by the use of and application thereto of moist heat, or heat in the form of steam at a pressure varying according to the size, of the stone, in combination with a bath of alum and Water, or with various baths composed of different chemicals and coloring; materials, substantially as described.

7. The process of causing stone to resemble or to acquire the appearance and uniform hardness and density throughout, or any of the qualities of natural marble, by the use of and application thereto of moist heat, or heat in the form of steam at a pressure varying according: to the size of the stone.

HARRIET GOODHUE IlOSMlilt.

\Vitnesses:

Jens \VILLIAM Gunmen,

I; Albert Road, Plaistozo. Jonu EDWARDS,

2S Ilatehmn Park Row, New (rose 

